Fuel injection system and associated structure

ABSTRACT

A fuel injection system and structure therefor, wherein a highpressure pump is used to inject fuel through the air intake valve structures of the engine. The valve structures are unique in many particulars, among which is the structural provision for valve displacement to effect air intake, as well as fuel injection through the valve stem at desired times directly into the associated cylinder. While the system lends itself to multiple piston pump operation, still, single piston pump operation is preferred for cost and maintenance considerations. A lost-motion structural provision is incorporated so as to insure the commencement of fuel injection immediately prior to valve opening as to air intake. A low pressure fuel return system is provided in the event of seal-leakage or failure in the valve stem structures. Timing as to fuel injection depends solely upon rocker-arm or other depression of the valves and, hence, is of simplified and yet highly effective form.

rated atent 1 1 on 3,812,829

McCormick 1 May 28, 1974 FUEL INJECTION SYSTEM AND PrimaryExaminer-Laurence M. Goodridge ASSOCIATED STRUCTURE AssistantExaminer-Ronald B. M. Cox

[76] Inventor: Alan G. McCormick, 645 Aloha,

Salt Lake City, Utah 84103 [57] ABSTRACT [22] Filed: Aug. 18, 1972 Afuel injection system and structure therefor,

21 Appl. No.: 281,770

wherein a-high-pressure pump is used to inject fuel through the airintake valve structures of the engine. The valve structures are uniquein many particulars, among which is the structural provision for valvedisplacement to effect air intake, as well as fuel injection through thevalve stem at desired times directly into the associated cylinder. Whilethe system lends itself to multiple piston pump operation, still, singlepiston pump operation is preferred for cost and maintenanceconsiderations. A lost-motion structural provision is incorporated so asto insure the commencement of fuel injection immediately prior to valveopening as to air intake. A low pressure fuel return system is providedin the event of seal-leakage or failure in the valve stem structures.Timing as to fuel injection depends solely upon rocker-arm or otherdepression of the valves and, hence, is of simplified and yet highlyeffective form.

8 Claims, 3 Drawing Figures /"'ro INTAKE MANI FOLD FUEL INJECTION SYSTEMAND ASSOCIATED STRUCTURE The present invention relates to fuel injectionsystems for internal combustion engines and, more particularly, to a newand improved fuel injection system and accommodating structure.

In the present invention, fuel injection is provided directly throughthe air intake valving structure of the engine. The valving structuresare modified such that these themselves contain valves to permit theselective injection of fuel directly into associated cylinders. Fuelinjection is thus directly related to rocker arm or other prime movermovement of the individual valves. Low pressure return means is employedas a safety feature such that in the event any seal-failure, or whereleakage past the seals occurs in the individual valve stems structures,such fuel will be returned via its own low pressure system to thelow-pressure fuel pump of the engine, for subsequent introduction to theoperative side of the high pressure pump utilized.

The system is designed to accommodate desired pressures of from 1,000 to4,000 psi, this to insure optimum atomization of fuel within theindividual cylinder chambers, for combustion purposes. When operating atsuch pressures. a maximum combustion as well as reduction ofcontaminants are achieved.

Accordingly, a principal object of the present invention is to provide anew and improved fuel injection system.

A further object is to provide improved structure design to accommodatefuel injection in internal combustion engines.

An additional object is to provide a fuel injection system wherein fuelis injected at high pressure directly into the cylinders of the engine.

An additional object is to provide for the introduction of high pressurefuel through the valving structure of an internal combustion engine.

A further object is to provide air intake valve structure for internalcombustion engines incorporating fuel injection, wherein the individualvalve structures themselves are provided with valves for permitting theselective introduction of fuel directly into the associated cylinders.

A further object is to provide in a valve structure a lost-motionconnection such that air inlet valve opening is time space from butclosely follows the commencement of fuel introduction under highpressure into the associated cylinder.

An additional object is to provide a low-pressure return system in afuel injection system incorporating fuel-travel passageways in valves,wherein seal failure or leakage will not cause any undue hazard as tosafety of operation.

An additional object is to provide a fuel injection system for aninternal combustion engine, such that modification of the internalcombustion engine itself is minimized in the incorporation of such fuelinjection system.

A further object is to provide a fuel injection system which by itsdesign precludes the necessity for complex fuel filtering.

The features of the present invention may best be understood byreference to the following description taken in connection with theaccompanying drawings in which:

FIG. 1 is a plan view of an internal combustion engine utilizing thesystem and structure of the present invention.

FIG. 2 is an end view taken along the line 2-2 in FIG. 1.

FIG. 3 is an enlarged fragmentary detail, principally in verticalsection, of a representative valve and valve stem, with surroundingstructure, illustrating the means by which fuel is injected into arespective cylinder.

FIG. 4 is an enlarged fragmentary detail taken along the arcuate line4-4 in FIG. 3.

In FIGS. 1 and 2 an internal combustion engine, modified in accordancewith the principles of the present invention, is shown. Accordingly, theinternal combustion engine 10 has its usual block 11 which for thepurposes of nomenclature may include also the valve head, pan l2, andcrankshaft 13 provided with pulley l4 keyed thereto. It will beunderstood that the engine structure will be conventional excepting forthe addition of the fuel injection system 15 comprising pump 16 and thepressure and return lines operatively associated therewith ashereinafter described. Specifically, pump 16 preferably comprises theinventors improved bellows pump as disclosed and claimed in a co-pendingUS. Pat. Application under the same title, executed by the inventor July25, 1972. There are several reasons for this preference among which arelow cost in manufacture, piston-bellows use for obtaining positivedisplacement, and a pump choice, consistent with the incorporation ofasingle piston, for supplying fuel to multiple cylinder cavities, anuncommon approach in fuel injection systems in general. Further, byemployment of such a pump, ease of maintenance is facilitated andmaintenance operations can be performed in any standard shop. For othertypes of fuel injection pump systems, such as the Bosch system, highlytrained personnel are required to maintain such pumps. Likewise, in theinventors pump design close tolerances are avoided. The foregoingobservations do not rule out the possibility of incorporating anothertype of pump design for pump 16. Thus, a Bosch pump, or indeed, anyother type of high pressure pump capable of pumping fuel at highpressure may be used. In the present instance, however, it is mostimportant to note that a single operating piston within the pumps designserves to effect a pumping of fuel to each of the cylinders of theengine. This will be described later in detail.

In any event, the preferred pumps design is that explained in theinventors above-referenced co-pending patent application which is nowfully incorporated herein by way of reference.

The high-pressure side 17 of the injection system is provided with apair of check valves 18 and 19, constructed and arranged in the usualmanner such as to permit a flow as shown by the'direction of arrows Aand B. Input drive shaft 20 for the pump 16 is provided with a pulley 21keyed thereto. Pulley 21 comprises a driven pulley that is connected bybelt 22 to pulley 14 associated with the crankshaft I3. Stub shaft 23 isappropriately journaled by suitable structure, not shown, for enablingthe securement of pulley 24. Shaft 23 will mount the usual fan 25. Stubconduit 26 leads to tee 27 which joins conduit 28 and 29. Conduit 28 andconduit 29 serve as pressure lines for fuel pumped to the respectivebanks of cylinders on opposite sides of the engine. Conduit 29 connectsto tee 30 that is simply plugged off by plug 31. Conduit 32,33 and 34are connected together as shown by tees 35, 36, 37 and 38. Tee 38 isplugged off at its outer end by plug 39 as indicated. Branch lines 4043are connected to their respective tees as indicated in FIG. 1.

The opposite or left-hand extremities of conduit 40-43 are connected totheir respective valve stem structures 44-47, either directly or viarespective flexible conduit 48 as secured to a representative conduit 40via coupling 49. For convenience of illustration the flexible connectionconduit 48 and coupling 49 are shown only in FIG. 2; FIG. 1 illustratesa direct connection of the respective conduit 4043, possibly flexible,to the respective valve stem structures 44-47. The high-pressure andlow-pressure line connections are il lustrated both in FIG. 1 and alsoin FIG. 3. To under stand the structural provisions involved, referenceis now made to FIG. 3.

In FIG. 3 it is seen that engine block 11 is provided with respectiveair intake valve stem bore 50 and guide 51. For convenience ofexplanation, only one of the valve structures of the engine will bedescribed and explained in detail. It will be understood that theremaining valves and remaining cylinders will likewise be constructed inessentially the same manner. Hence, the representation in FIG. 3 istypical of all valve guide structures.

As seen in FIG. 3, representative high-pressure conduit 40 isoperatively connected to fitting 52. The latter is provided with atransverse bore 53 that receives valve stem 54. Valve stem 54 includes,of course, radial apertures 55 and 56. These latter register withapertures 57 and 58 of valve stem liner 59. O-ring seals at 60 and 61are provided in O-ring grooves 62 and 63, as indicated. Low-pressureconduit 64 includes a corresponding fitting 65 having an interior groove66 cooperatively associated with radial apertures 67 of valve stem 54.The valve stem 54 is interiorly threaded at 68 to receive externallythreaded plug 69. The latter includes a relief bore 70 for receivingthreaded shaft 71. No threaded engagement exists between threaded shaft71 and this bore. In any event, threaded shaft 71 is threaded into axialthreaded aperture 72 of the valve stem liner 59. A compression spring 73is operatively disposed between the upper end of threaded plug 69 andinner surface 74 of spring retainer 75.

Valve return spring 76 is a compression spring operatively disposedbetween engine block 11 and spring retainer 77. Spring retainer 77 isretained in position by conventional, split spring-retainer lock 78.

The lower portion of FIG. 3 and also FIG. 4 disclose the pintle valvestructure at the lower portion thereof. Specifically, valve member 79includes, of course, not only the valve stem 54 but also valve portion80 integral therewith. The valve portion 80 is threaded at threadedaperture 81 to receive valve plug 82. Valve plug 82 is provided with keyslots 83 so that the plug may be threadedly turned in position. Plug 82includes a pintle seat 84 communicating with fuel passageway 85; thelatter may be chamfered at 86 if desired. Pintle 87 is threaded at 88and is received in threaded aperture 89 of valve stem liner 59. Thelatter thus is seen to be of tubular construction which is closed at itslower end. Valve stem liner 59 includes plural radial passageways 90 and91 which communicate with longitudinal exterior surface grooves 92 and93. The construction is such that fuel passageway space 94 is pro vided.

In operation, valve member 79 comprises the air inlet valve of theengine; thus, though there is no carburetor in the engine, since thiscomprises a fuel injection system: nonetheless, cavity 95 will lead tothe conventional intake manifold of the engine. Hence, as valve 80descends, air is drawn into the associated cylinder. It will be noted,however, with the descent of such valve poppet 80, fuel also comesthrough the valve via conduit 40. In describing fully this operation itwill be seen that the aligned apertures proximate the fitting 52 willadmit fuel from'the high pressure conduit 40 such that such fuel entersthe interior passageway 96 of valve stem liner 59. This fuel is underpressure and proceeds downwardly to radial passageways 90 and 91, forexample, proceeding therefrom through slot passageways 92 and 93 intofuel area 94.

In considering FIG. 2 in conjunction with FIG. 3, it is most importantto note that conventional rocker arm or other prime mover 97, ofstandard construction in the engine, not only serves to depress theover-all representative valve member 79 but, in addition, to spacedlylower the pintle 87 relative to the pintle seat 84 of the valve. This isaccomplished by virtue of the fact that a depression of cap nut 98,threaded onto shaft 71, will effect, first, a depression of the valvestem liner 59and, associatively, pintle 87, just prior to the time thatinterior shoulder 99 engages the upper extremity of valve stem 54. Uponsuch engagement, then the rocker arm, in its further travel, willseparate or lower the valve portion 80 from its seat at 100, allowingair to enter cylinder.

It is important that the space 101 between the aforementioned shoulderand valve stem be made adjustable, so that the fuel flow through thepintle valve at 87 can be adjusted. The purpose for the inclusion ofspring 73 and cap nut 98 is to close pintle 87 against its seat.

The purpose for the inclusion of the low-pressure system as at 64 willnow be explained. It is noted that we are dealing with high pressurefuel injection. In the absence of the inclusion of a low-pressuresystem, then, should the seals fail as at O-rings 60 and 61, there wouldbe a chance of leakage out of the upper portion of the valve stemstructure, possibly rendering a dangerous condition for the engine. Toavoid such a difficulty, the inventor includes at each valve stemstructure a fitting 65 and a representative conduit 64, all of which areconnected together and lead to conduit 102. The latter in turn connectsto tee 103 which joins to the remaining low-pressure side of the enginevia conduit 104 and also to the input conduit 105 of conventionallow-pressure fuel pump 106, i.e., the same incorporated to draw gasolinefrom the engine. The output of low-pressure fuel pump 106, at 107, isconnected via conduit 108 to the input side 17 of the high pressure fuelinjection pump 16 of the present invention. Line 105 simply leads to thefuel supply for the engine. The structure at C in FIG. I is identical tothe structure at E and simply accommodates the remaining bank ofcylinders of the engine. Accelerator rod 109 leads to the footaccelerator of the vehicle and is connected at its forward extremity toan acceleration control 110 via pivot connection 111. The accelerationcontrol at 110 will simply connect to the volume control of pumpedliquid, herein fuel, as is customarily supplied the pump.

See by way of example the displacement volume adjustmerit control of theinventors co-pending application above referenced, herein incorporatedfully by way of reference.

Accordingly, the present invention provides a conventional internalcombustion engine, having valve displacement rocker arm structure, withnew and improved valve structure that facilitates the valve introductionof air flow and also fuel injection upon such air introduction. It isnoted that fuel injection is begun just prior to air inlet valveopening, which affords a maximum combustion effect for the particularcylinder in question. Further, no complicated timing problems arepresented relative to the fuel injection since the same relies upon therocker arm movement for effecting the necessary fuel injection atdesired times. Timing will be wholly controlled by the settings of therocker arms.

What is provided hence is a new and improved system and structure forfuel injection wherein the fuel injected comes actually through the airintake valve stems of the engine.

While particular embodiments of the invention have been shown anddescribed, it will be obvious to those skilled in the art the variouschanges and modifications which may be made without departing from theessential features of the present invention and, therefore, the aim inthe appended claims is to cover all such changes and modifications asfall within the true spirit and scope of the invention.

l claim:

1. In an internal combustion engine having a cylinder block providedwith air-intake valve bores and means for cyclically depressingindividual valve structures disposed in respective ones of said bores:an improvement comprising fuel injection pump means, having input andoutput sides, for operatively introducing fuel into said cylinder block;plural air intake valve structures individual ones of which are disposedin respective ones of said air-intake valve bores, each of said airintake valve structures comprising an air valve member having a valvestem and an air intake valve portion integral therewith, and providedwith a fuel valve seat said air valve member being provided with fuelpassageway means disposed axially through said valve stem and an airintake valve portion; and conduit means interconnecting said fuelinjection pump means at said output side with said valve structures, andwherein each of said air intake valve structures includes a hollow valvestem liner, a fuel valve pintle connected to said valve stem liner andseated in said fuel valve seat, and a single mechanical member forcyclically, thrustingly depressing said valve stem liner relative tosaid valve stem and said valve stem relative to said cylinder block.

2. Structure according to claim 1 wherein each of said valve stems andsaid valve stem liners are provided with seal means disposedtherebetween, plural fittings respective ones of which are disposedabout said valve stems above said seal means, said valve stems beingprovided with respective passageway means for provid' ing communicationbetween the interior of said valve stems above said seal means and saidfittings, and conduit means coupling all of said fittings back to saidfuel injection pump means at the input side thereof.

3. Structure according to claim 1 wherein said valve stem includes aplug having an axial guide aperture, spring retainer means disposedabove said plug, a compression spring disposed between said springretainer means and said plug. and a shaft fixedly disposed with respectto said valve stem liner and said spring retainer means and passingthrough said axial guide aperture.

4. The combination of claim 1 wherein said air valve portion has a lowerthreaded plug seat, a plug threaded into said plug seat and having adownwardly facing valve seat as said fuel valve seat and a centralpassageway communicating therewith, said fuel valve pintle being seatedin said downwardly facing valve seat and being secured to said valvestem liner, said valve stem liner having fuel passageway means providingcommunication between the exterior of said fuel valve pintle and thehollow interior of said valve stem liner.

5. In an internal combustion engine having a cylinder block providedwith air-intake valve bores and means for cyclically depressingindividual valve structures disposed in respective ones of said bores;an improvement comprising fuel injection pump means, having input andoutput sides, for operatively introducing fuel into said cylinder block;plural air intake valve structures individual ones of which are disposedin respective ones of said air-intake valve bores, each of said airintake valve structures comprising an air a valve member having a valvestem and intake valve portion integral therewith, said air valve memberbeing provided with fuel passageway means disposed axially through saidvalve stem and air intake valve portion; and conduit meansinterconnecting said fuel injection pump at said output side with saidvalve structures, said valve stem includes a plug having an axial guideaperture, spring retainer means disposed above said plug, a compressionspring disposed between said spring retainer means and said plug, and ashaft fixedly disposed with respect to said valve stem liner and saidspring retainer means and passing through said axial guide aperture, andwherein said spring retainer means comprises a cap-configured retainerhaving a lost-motion interior shoulder, said shoulder being dimensionedto cyclically abut the combination of said plug and said valve stem.

6. In combination, an internal combustion engine having at least one,air-intake valve bore having a valve seat; at least one air intake valvestructure disposed in respective one of said bore and having an airintake valve portion; a single mechanical member for structurallydepressing said valve structure, said air intake valve structures havinginterior passageway means for conducting fuel through such air intakevalve structure to the interior of said engine; a fuel injection pump;and conduit means for coupling said fuel injection pump to said valvestructure, and wherein said air intake valve structure includes a valvestem having an integral air admitting valve poppet portion and is itselfinteriorly provided with interior fuel admittance valving means disposedproximate to and operative in connection with said interior passagewaymeans, and structural means actuated by said single mechanical memberfor enabling opening of said interior valving means prior to depressionof the valve stem operatively associated therewith.

7. Structure according to claim 6 wherein bypass means is provided forconveying leakage fuel, from the interior of said valve stem, back tosaid fuel injection pump means.

8. In combination, an internal combustion engine having plural,air-intake valve bores having valve seats; plural air intake valvestructures disposed in respective ones of said bores and having airintake valve portions;

mechanical means for sequentially structurally depressing said valvestructures, said air intake valve structures having interior passagewaymeans for conducting fuel through such air intake valve structures tothe interior valve structures, and wherein said valve structure haslost-motion structural means enabling, upon downward thrusting of saidvalve structure, first, opening of said valve structure interior and,second, depression of said of said engine; a fuel injection pump; andconduit valve stem and said valve portion from its valve seat.

1. In an internal combustion engine having a cylinder block providedwith air-intake valve bores and means for cyclically depressingindividual valve structures disposed in respective ones of said bores:an improvement comprising fuel injection pump means, having input andoutput sides, for operatively introducing fuel into said cylinder block;plural air intake valve structures individual ones of which are disposedin respective ones of said air-intake valve bores, each of said airintake valve structures comprising an air valve member having a valvestem and an air intake valve portion integral therewith, and providedwith a fuel valve seat said air valve member being provided with fuelpassageway means disposed axially through said valve stem and an airintake valve portion; and conduit means interconnecting said fuelinjection pump means at said output side with said valve structures, andwherein each of said air intake valve structures includes a hollow valvestem liner, a fuel valve pintle connected to said valve stem liner andseated in said fuel valve seat, and a single mechanical member forcyclically, thrustingly depressing said valve stem liner relative tosaid valve stem and said valve stem relative to said cylinder block. 2.Structure according to claim 1 wherein each of said valve stems and saidvalve stem liners are provided with seal means disposed therebetween,plural fittings respective ones of which are disposed about said valvestems above said seal means, said valve stems being provided withrespective passageway means for providing communication between theinterior of said valve stems above said seal means and said fittings,and conduit means coupling all of said fittings back to said fuelinjection pump means at the input side thereof.
 3. Structure accordingto claim 1 wherein said valve stem includes a plug having an axial guideaperture, spring retainer means disposed above said plug, a compressionspring disposed between said spring retainer means and said plug, and ashaft fixedly disposed with respect to said valve stem liner and saidspring retainer means and passing through said axial guide aperture. 4.The combination of claim 1 wherein said air valve portion has a lowerthreaded plug seat, a plug threaded into said plug seat and having adownwardly facing valve seat as said fuel valve seat and a centralpassageway communicating therewith, said fuel valve pintle being seatedin said downwardly facing valve seat and being secured to said valvestem liner, said valve stem liner having fuel passageway means providingcommunication between the exterior of said fuel valve pintle and thehollow interior of said valve stem liner.
 5. In an internal combustionengine having a cylinder block provided with air-intake valve bores andmeans for cyclically depressing individual valve structures disposed inrespective ones of said bores; an improvement comprising fuel injectionpump means, having input and output sides, for operatively introducingfuel into said cylinder block; plural air intake valve structuresindividual ones of which are disposed in respective ones of saidair-intake valve bores, each of said air intake valve structurescomprising an air a valve member having a valve stem and intake valveportion integral therewith, said air valve member being provided withfuel passageway means disposed axially through said valve stem and airintaKe valve portion; and conduit means interconnecting said fuelinjection pump at said output side with said valve structures, saidvalve stem includes a plug having an axial guide aperture, springretainer means disposed above said plug, a compression spring disposedbetween said spring retainer means and said plug, and a shaft fixedlydisposed with respect to said valve stem liner and said spring retainermeans and passing through said axial guide aperture, and wherein saidspring retainer means comprises a cap-configured retainer having alost-motion interior shoulder, said shoulder being dimensioned tocyclically abut the combination of said plug and said valve stem.
 6. Incombination, an internal combustion engine having at least one,air-intake valve bore having a valve seat; at least one air intake valvestructure disposed in respective one of said bore and having an airintake valve portion; a single mechanical member for structurallydepressing said valve structure, said air intake valve structures havinginterior passageway means for conducting fuel through such air intakevalve structure to the interior of said engine; a fuel injection pump;and conduit means for coupling said fuel injection pump to said valvestructure, and wherein said air intake valve structure includes a valvestem having an integral air admitting valve poppet portion and is itselfinteriorly provided with interior fuel admittance valving means disposedproximate to and operative in connection with said interior passagewaymeans, and structural means actuated by said single mechanical memberfor enabling opening of said interior valving means prior to depressionof the valve stem operatively associated therewith.
 7. Structureaccording to claim 6 wherein bypass means is provided for conveyingleakage fuel, from the interior of said valve stem, back to said fuelinjection pump means.
 8. In combination, an internal combustion enginehaving plural, air-intake valve bores having valve seats; plural airintake valve structures disposed in respective ones of said bores andhaving air intake valve portions; mechanical means for sequentiallystructurally depressing said valve structures, said air intake valvestructures having interior passageway means for conducting fuel throughsuch air intake valve structures to the interior of said engine; a fuelinjection pump; and conduit means for coupling said fuel injection pumpto said valve structures, and wherein said valve structure haslost-motion structural means enabling, upon downward thrusting of saidvalve structure, first, opening of said valve structure interior and,second, depression of said valve stem and said valve portion from itsvalve seat.